Vacuum cleaner with a microprocessor-based dirt detection circuit

Abstract

A vacuum cleaner for providing visual operational status indicators includes a vacuum cleaner having internal components that are indicative of the cleaner's performance. Sensors are coupled to at least one of the internal components to be monitored. A microprocessor receives input from the sensors, analyzes the input, and generates an output signal. Visual indicators are carried by the vacuum cleaner and receive the output signals to display the operational status of the vacuum.

What is claimed is:  
     
       1. A vacuum cleaner having an operational status indicator arrangement, the vacuum cleaner having a motor fan assembly for generating an airstream originating at a suction nozzle for removing dirt particles from a surface, a dirt particle filtering and collecting arrangement, and at least one conduit fluidly connecting the motor fan assembly, the suction nozzle and the dirt filtering and collecting arrangement, the operational status indicator arrangement comprising: 
       at least one sensor for detecting an operational status of the vacuum cleaner;  
       a microprocessor for receiving an input signal from said at least one sensor, comparing said input signal over a plurality of pre-determined time intervals to a threshold value, wherein said microprocessor has a pair of counters with corresponding maximum and minimum values, with said first counter initially set to a maximum first counter value, and said second counter initially set to maximum second counter value, wherein said second counter is decremented each time said input signal exceeds said threshold value and a flag is set when said second counter reaches said minimum second counter value and said first counter is again set to said first counter maximum value when said second counter is decremented a successive number of times equal to the maximum second counter value; and  
       at least one indicator carried by said vacuum cleaner for indicating an operational status of said vacuum cleaner;  
       wherein said at least one indicator indicates the operational status when said flag is set.  
     
     
       2. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said first counter is decremeted each time said input signal is less than said threshold value and said flag is reset when said first counter reaches said first counter minimum value and said second counter is reset to a maximum second counter value when said first counter is decremented a successive number of times equal to the maximum first counter value. 
     
     
       3. The vacuum cleaner having an operational status indicator arrangement of  claim 2 , said at least one indicator comprises a pair of lights, each of said pair of lights having one or more states including at first state wherein said light is illuminated and a second state wherein said light is turned off, wherein when one of said pair of lights is illuminated the other of said pair of lights is turned off, wherein one of said pair of lights is illuminated for a minimum of a predetermined time interval when said flag is set and the other of said pair of lights is illuminated after said one of said pair of lights is turned off. 
     
     
       4. The vacuum cleaner having an operational status indicator arrangement of  claim 2 , wherein said first counter is reset to said maximum first counter value if said input signal exceeds said threshold value after said first counter has been decremented. 
     
     
       5. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said second counter is reset to a maximum second counter value each time said first counter is decremented. 
     
     
       6. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said at least one indicator indicates the operational status for a minimum predetermined time interval after said flag has been set. 
     
     
       7. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said at least one conduit includes a tube coupled to said motor fan assembly and said dirt filtering and collecting arrangement is a bag coupled to said tube for filtering and collecting dirt from said airstream. 
     
     
       8. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said at least one sensor is a microphone. 
     
     
       9. The vacuum cleaner having an operational status indicator arrangement of  claim 8 , wherein said microphone is coupled to said tube, said microphone detecting noise generated by dirt moving through said tube and generating said input signal. 
     
     
       10. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , further comprising a sensitivity switch carried by said vacuum cleaner and connected to said microprocessor, said sensitivity switch having a plurality of positions corresponding to a desired amount of sensitivity related to the operational status of the vacuum cleaner and adjusting said threshold value to a threshold value corresponding to the position of said sensitivity switch. 
     
     
       11. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , further comprising a sensitivity switch carried by said vacuum cleaner and connected to said microprocessor, said, sensitivity switch having a plurality of positions corresponding to a desired amount of sensitivity related to the operational status of the vacuum cleaner and assigning a maximum first counter value and maximum second counter value corresponding to the position of said sensitivity switch. 
     
     
       12. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said at least one indicator comprises a pair of lights, one of said lights illuminating when said flag is set, otherwise the other of said lights is illuminated. 
     
     
       13. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said second counter is reset to said maximum second counter value if said input signal is less than said threshold value after said second counter has been decremented. 
     
     
       14. The vacuum cleaner having an operational status indicator arrangement of  claim 1 , wherein said flag is a dirt present flag. 
     
     
       15. A vacuum cleaner having an operational status indicator system, the vacuum cleaner having a motor fan assembly for generating an airstream originating at a suction nozzle for removing dirt particles from a surface, a dirt particle filtering and collecting arrangement, and at least one conduit fluidly connecting the motor fan assembly, the suction nozzle and the dirt filtering and collecting arrangement, the operational status indicator system comprising: 
       at least one sensor for detecting an operational status of the vacuum cleaner;  
       a microprocessor for receiving an input signal from said at least one sensor, comparing said input signal over a plurality of pre-determined time intervals to a threshold value, wherein said microprocessor has a counter with corresponding maximum and minimum values, with said counter initially set to a minimum counter value, wherein said counter is incremented each time said input signal exceeds said threshold value and a flag is set when said counter reaches said maximum counter value; and  
       at least one indicator carried by said vacuum cleaner for indicating an operational status of said vacuum cleaner;  
       wherein said at least one indicator indicates the operational status when said flag is set.  
     
     
       16. The vacuum cleaner having an operational status indicator system of  claim 15 , wherein said counter is decremented each time said input signal is less than said threshold value and said flag is reset when said counter has been decremented a number of times equal to the maximum counter value. 
     
     
       17. The vacuum cleaner having an operational status indicator system of  claim 15 , wherein said at least one conduit includes a tube coupled to said motor fan assembly and said dirt filtering and collecting arrangement is a bag coupled to said tube for filtering and collecting dirt from said airstream. 
     
     
       18. The vacuum cleaner having an operational status indicator system of  claim 15 , wherein said at least one sensor is a pressure transducer coupled to said bag, said pressure transducer detecting a pressure level in said bag and generating said input signal for comparison to said threshold value. 
     
     
       19. The vacuum cleaner having an operational status indicator system of  claim 15 , further comprising a sensitivity switch carried by said vacuum cleaner and connected to said microprocessor, said sensitivity switch having a plurality of positions corresponding to a desired amount of sensitivity related to the operational status of the vacuum cleaner and adjusting said threshold value to a threshold value corresponding to the position of said sensitivity switch. 
     
     
       20. The vacuum cleaner having an operational status indicator system of  claim 15 , further comprising a sensitivity switch carried by said vacuum cleaner and connected to said microprocessor, said sensitivity switch having a plurality of positions corresponding to a desired amount of sensitivity related to the operational status of the vacuum cleaner and assigning said maximum counter value corresponding to the position of said sensitivity switch. 
     
     
       21. The vacuum cleaner having an operational status indicator system of  claim 15 , said at least one indicator comprises a light having one or more states including a first state and a second state, the first state being illuminated and the second state being turned off, said light being illuminated when said flag is set and turned off when said flag is reset. 
     
     
       22. The vacuum cleaner having an operational status indicator of  claim 15 , wherein said flag is a bag full flag. 
     
     
       23. The vacuum cleaner having an operational status indicator system of  claim 15 , wherein the at least one sensor is positioned within an inlet to the motor fan assembly and monitors a pressure differential across said inlet. 
     
     
       24. A cleaner having an operational indicator system, comprising: 
       a suction nozzle;  
       a motor fan assembly for generating an airstream originating at the suction nozzle for removing dirt from a surface;  
       a conduit fluidly connected at one end to said motor fan assembly;  
       a bag fluidly connected to said conduit for collecting the dirt removed by said suction nozzle;  
       at least one sensor associated with said bag to monitor the amount of dirt therein, said at least one sensor generating an input signal;  
       a microprocessor for receiving at least one input signal from said at least one sensor, comparing said input signal to a threshold value, said microprocessor including a counter having a maximum value and a minimum value; and  
       an indicator;  
       wherein said counter is initially set at said minimum value and incremented each time said at least one input signal exceeds said threshold value and said indicator indicates an operational status of said cleaner when said counter attains said maximum value.  
     
     
       25. The cleaner according to  claim 24 , wherein said counter is decremented each time said at least input signal is less than said threshold value and said indicator is turned off when said counter is decremented to said minimum value. 
     
     
       26. The cleaner according to  claim 24 , wherein the sensor is positioned within an inlet to the motor fan assembly and monitors a pressure differential across said inlet. 
     
     
       27. A floor care appliance having an operational status indicator system, the floor care appliance having a motor fan assembly for generating an airstream originating at a suction nozzle for removing dirt particles from a surface, a dirt particle filtering and collecting arrangement, and at least one conduit fluidly connecting the motor fan assembly, the suction nozzle and the dirt filtering and collecting arrangement, the operational status indicator system comprising: 
       at least one sensor for detecting an operational status of the vacuum cleaner;  
       a microprocessor for receiving at least one input signal from said at least one sensor, comparing said at least one input signal to a threshold value, wherein said microprocessor has at least one counter having a minimum and maximum counter value, wherein said at least one counter is decremented each time said at least one input signal exceeds said threshold value and a flag is set when said at least one counter reaches said minimum counter value; and  
       at least one indicator carried by said floor care appliance for indicating an operational status of said floor care appliance;  
       wherein said at least one indicator indicates an operational status of said floor care appliance when said flag is set.  
     
     
       28. A floor care appliance having an operational status indicator system, the floor care appliance having a motor fan assembly for generating an airstream originating at a suction nozzle for removing dirt particles from a surface, a dirt particle filtering and collecting arrangement, and at least one conduit fluidly connecting the motor fan assembly, the suction nozzle and the dirt filtering and collecting arrangement, the operational status indicator system comprising: 
       at least one sensor for detecting an operational status of the vacuum cleaner;  
       a microprocessor for receiving at least one input signal from said at least one sensor, comparing said at least one input signal to a threshold value, and generating an output based upon the number of times said at least one input signal exceeds or falls below said threshold value; and  
       at least one indicator carried by said floor care appliance for indicating an operational status of said floor care appliance;  
       wherein said at least one indicator indicates an operational status of said floor care appliance based upon said output signal.  
     
     
       29. A method of indicating the presence of dirt being picked up by a vacuum source, said method including the steps of: 
       creating an airflow with the vacuum source, said airflow travels through an airflow path;  
       providing a microphone within said air flow path, said microphone detects the presence of dirt within said air flow path and generates an AC audio signal;  
       converting said AC audio signal to a mean DC value using a diode pump circuit;  
       transmitting said mean DC value to a microprocessor;  
       comparing said mean DC value to a threshold level; and  
       illuminating a visual indicator when said mean DC value exceeds said threshold level.